Also, my maintainer tool now has added support for the Alpine Linux distribution, thanks to help by one of its maintainers: Natanael Copa.
This is meant to help all cross-distro collaboration, not just for reproducible builds.

There is still work to be done to make better use of Mitre CPE to map package names across distributions.

I think, one major benefit of the summit was all the networking and talking going on, so that we have an easier time working with each other over the internet in the future.